1. Field of the Invention
The present invention relates to a data communication apparatus for transmitting data such as image data or text code data through a communication line.
2. Description of the Prior Art
In a prior art apparatus of this type, an image of an original document was usually transmitted in real time, but as semiconductor technology advanced, it has become possible to temporarily store the image of the original document in a memory and to transmit it from the memory. Thus, an apparatus having both the real-time transmission mode and the memory transmission mode has been proposed. However, in the real-time transmission mode, an operator is not released from the apparatus if a communication line is busy, and in the memory transmission mode, the operation is complex and time-consuming because the image of the original document is stored in the memory irrespective of the busy or non-busy state of the communication line or the image of the original document is sent to the memory after the operator observes the busy state of the communication line.